1. Field of the Invention
The present invention is related to a supporting structure, in particular, for attachment to robot arms and for securing tools such as clamping, gripping and suction devices or other equipment, such as valves, sensors and the like, and more particularly is related towards elements provided on such supporting structures for precisely positioning the same relative to one another.
2. Description of the Prior Art
Supporting structures or supporting devices of the afore-described type have been taught, for example, by German Patent Application No. 28 06 557. Supporting structures or structure building systems of this type which, conventionally and as a rule, are attached to robot arms, are used for transporting workpieces (e.g. body sheets) from one processing location to another, with one of the mandatory requirements being the precise seizure and deposition of the workpieces in addition to the basic variability requirement to enable such equipment to adapt to existing local conditions and special workpiece designs, and also to comply with specific space orientations of the workpieces. The conventional systems of this type appear to comply only inadequately with the afore-described requirements. Concerning supporting structure building systems of a similar design reference is, in addition, made to UK Patent Application No. 2 275 737 and German Patent Application 37 36 266 A1.
In respect of supporting structures composed of shaped bars and clamping elements it is of importance that the clamping members, irrespective of whether they interconnect two bars or whether they serve as supports for special tools on bars, be precisely positioned with respect to one another, proceeding, as a rule, from a predetermined point of reference of, e.g. a robot arm carrying the entire supporting structure and moving the same into the most different positions. Especially when attached to a robot arm, it is, moreover, important that the position of the bars and of the clamping members once adjusted with respect to one another be precisely reproducible in case of displacement of the predetermined adjustment of the clamping members which is likely to occur in case of interference with an obstacle.
This precise positioning and reproducibility requirement, hitherto, has been met by conventional supporting structures of the afore-mentioned type only inadequately and in a time-consuming way, yielding more or less precise results by using measuring poles, inch rules, tape measures and the like equipment to measure the distances of suitable edges or rims of the clamping members and then fixing the same on the bars.
It is, therefore, a primary object of the present invention to provide a new and improved supporting structure which overcomes the deficiencies noted above with respect to the prior-art supporting structures.
Another object of the present invention is to provide an improved supporting structure wherein the required positioning, initially, can be performed independently of the clamping members on the bars whereafter the clamping members are moved to the adjusted positions and fixed therein in an oriented way. An additional object of the present invention is to provide an improved supporting structure readily enabling a precise reproduction of pre-adjusted positions of the clamping members.
A still further object of the present invention is to provide an improved supporting structure of a design such that displacements, if any, of the clamping members are automatically detected.
The afore-going and other objects are attained in accordance with one aspect of the present invention through the provision of a supporting structure, which comprises the following features:
arranged within the groove is an adjusting strip adapted to be clamped therein, and provided both within the clamping member and within the adjusting strip, for accommodating an adjusting pin, are adjusting ports adapted to be placed in registry by a relative displacement of adjusting strip and clamping member.
The supporting structure of the invention will meet the requirements placed upon the same, as it is no longer the clamping members as such but only the strips or lockers that will have to be adjusted involving substantially less efforts as the adjusting ports are available for positioning the strips. For precisely adjusting the distance between two strips by a given measure, a special scale is used which comprises two small cones adjusted to the precise distance required and centrally insertable into the adjusting ports of the strips. Once the two strips are fixed in this position within their groove, the clamping members are then mounted in an approximately corresponding position on the respective bar and with the aid of an adjusting pin are placed into the precise position in that the said pin is first pushed into the adjusting port of the clamping member and after being placed in registry with the adjusting port provided in the strip is also pushed thereinto.
Preferably, the end of the adjusting pin to be inserted is of a slightly conical configuration. However, also the edge of the adjusting port within the strip can be of a slightly conically chamfered configuration yet to be explained in closer detail hereinafter.
After an adjusted association of the clamping members to the respective strip, the clamping members are fixed to the bar to then again draw, i.e. remove, the adjusting pin.
This will not only readily permit an accurate positioning of the clamping members but will also enable such accurate position, if need be, to be reproduced without requiring any re-measuring steps as the strips remain within the grooves of the bars in a position precisely adjusted and fixed even if the clamping members have been displaced for whatever reason.